diff --git a/backend/resources/migrations/postgres/20260102231700_ldap_admin_group_rename.up.sql b/backend/resources/migrations/postgres/20260102231700_ldap_admin_group_rename.up.sql
index 4a92606d..99259449 100644
--- a/backend/resources/migrations/postgres/20260102231700_ldap_admin_group_rename.up.sql
+++ b/backend/resources/migrations/postgres/20260102231700_ldap_admin_group_rename.up.sql
@@ -1 +1,8 @@
-UPDATE app_config_variables SET key = 'ldapAdminGroupName' WHERE key = 'ldapAttributeAdminGroup';
+UPDATE app_config_variables
+SET key = 'ldapAdminGroupName'
+WHERE key = 'ldapAttributeAdminGroup'
+  AND NOT EXISTS (
+    SELECT 1
+    FROM app_config_variables
+    WHERE key = 'ldapAdminGroupName'
+);
\ No newline at end of file
diff --git a/backend/resources/migrations/sqlite/20251217141000_v2_export_normalization.up.sql b/backend/resources/migrations/sqlite/20251217141000_v2_export_normalization.up.sql
index 1eae6c6f..2aa0b52b 100644
--- a/backend/resources/migrations/sqlite/20251217141000_v2_export_normalization.up.sql
+++ b/backend/resources/migrations/sqlite/20251217141000_v2_export_normalization.up.sql
@@ -10,8 +10,8 @@ CREATE TABLE users_new
     id           TEXT                  NOT NULL PRIMARY KEY,
     created_at   DATETIME,
     username     TEXT COLLATE NOCASE   NOT NULL UNIQUE,
-    email        TEXT                  NOT NULL UNIQUE,
-    first_name   TEXT,
+    email        TEXT UNIQUE,
+    first_name   TEXT                  NOT NULL,
     last_name    TEXT                  NOT NULL,
     display_name TEXT                  NOT NULL,
     is_admin     BOOLEAN DEFAULT FALSE NOT NULL,
diff --git a/backend/resources/migrations/sqlite/20260102231700_ldap_admin_group_rename.up.sql b/backend/resources/migrations/sqlite/20260102231700_ldap_admin_group_rename.up.sql
index 800371fd..981d0a97 100644
--- a/backend/resources/migrations/sqlite/20260102231700_ldap_admin_group_rename.up.sql
+++ b/backend/resources/migrations/sqlite/20260102231700_ldap_admin_group_rename.up.sql
@@ -1,7 +1,14 @@
 PRAGMA foreign_keys= OFF;
 BEGIN;
 
-UPDATE app_config_variables SET key = 'ldapAdminGroupName' WHERE key = 'ldapAttributeAdminGroup';
+UPDATE app_config_variables
+SET key = 'ldapAdminGroupName'
+WHERE key = 'ldapAttributeAdminGroup'
+  AND NOT EXISTS (
+    SELECT 1
+    FROM app_config_variables
+    WHERE key = 'ldapAdminGroupName'
+);
 
 COMMIT;
 PRAGMA foreign_keys= ON;
diff --git a/backend/resources/migrations/sqlite/20260103142200_user_nullable_fields.down.sql b/backend/resources/migrations/sqlite/20260103142200_user_nullable_fields.down.sql
new file mode 100644
index 00000000..f8e19576
--- /dev/null
+++ b/backend/resources/migrations/sqlite/20260103142200_user_nullable_fields.down.sql
@@ -0,0 +1 @@
+-- No-op
\ No newline at end of file
diff --git a/backend/resources/migrations/sqlite/20260103142200_user_nullable_fields.up.sql b/backend/resources/migrations/sqlite/20260103142200_user_nullable_fields.up.sql
new file mode 100644
index 00000000..1b5d29a1
--- /dev/null
+++ b/backend/resources/migrations/sqlite/20260103142200_user_nullable_fields.up.sql
@@ -0,0 +1,52 @@
+PRAGMA foreign_keys= OFF;
+BEGIN;
+
+CREATE TABLE users_new
+(
+    id           TEXT                  NOT NULL PRIMARY KEY,
+    created_at   DATETIME,
+    updated_at   DATETIME,
+    username     TEXT COLLATE NOCASE   NOT NULL UNIQUE,
+    email        TEXT UNIQUE,
+    first_name   TEXT                  NOT NULL,
+    last_name    TEXT                  NOT NULL,
+    display_name TEXT                  NOT NULL,
+    is_admin     BOOLEAN DEFAULT FALSE NOT NULL,
+    ldap_id      TEXT UNIQUE,
+    locale       TEXT,
+    disabled     BOOLEAN DEFAULT FALSE NOT NULL
+);
+
+INSERT INTO users_new (
+    id,
+    created_at,
+    updated_at,
+    username,
+    email,
+    first_name,
+    last_name,
+    display_name,
+    is_admin,
+    ldap_id,
+    locale,
+    disabled
+) SELECT
+    id,
+    created_at,
+    updated_at,
+    username,
+    email,
+    first_name,
+    last_name,
+    display_name,
+    is_admin,
+    ldap_id,
+    locale,
+    disabled FROM users;
+
+DROP TABLE users;
+ALTER TABLE users_new RENAME TO users;
+
+
+COMMIT;
+PRAGMA foreign_keys= ON;